Convert busy_count to a simple int protected by spinlock.
Reviewed-by: Steven Price steven.price@arm.com Reviewed-by: Alyssa Rosenzweig alyssa.rosenzweig@collabora.com Signed-off-by: Clément Péron peron.clem@gmail.com --- drivers/gpu/drm/panfrost/panfrost_devfreq.c | 43 +++++++++++++++------ drivers/gpu/drm/panfrost/panfrost_devfreq.h | 9 ++++- 2 files changed, 40 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.c b/drivers/gpu/drm/panfrost/panfrost_devfreq.c index 962550363391..78753cfb59fb 100644 --- a/drivers/gpu/drm/panfrost/panfrost_devfreq.c +++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.c @@ -12,16 +12,12 @@
static void panfrost_devfreq_update_utilization(struct panfrost_devfreq *pfdevfreq) { - ktime_t now; - ktime_t last; - - if (!pfdevfreq->devfreq) - return; + ktime_t now, last;
now = ktime_get(); last = pfdevfreq->time_last_update;
- if (atomic_read(&pfdevfreq->busy_count) > 0) + if (pfdevfreq->busy_count > 0) pfdevfreq->busy_time += ktime_sub(now, last); else pfdevfreq->idle_time += ktime_sub(now, last); @@ -59,10 +55,14 @@ static int panfrost_devfreq_get_dev_status(struct device *dev, { struct panfrost_device *pfdev = dev_get_drvdata(dev); struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq; + unsigned long irqflags; + + status->current_frequency = clk_get_rate(pfdev->clock); + + spin_lock_irqsave(&pfdevfreq->lock, irqflags);
panfrost_devfreq_update_utilization(pfdevfreq);
- status->current_frequency = clk_get_rate(pfdev->clock); status->total_time = ktime_to_ns(ktime_add(pfdevfreq->busy_time, pfdevfreq->idle_time));
@@ -70,6 +70,8 @@ static int panfrost_devfreq_get_dev_status(struct device *dev,
panfrost_devfreq_reset(pfdevfreq);
+ spin_unlock_irqrestore(&pfdevfreq->lock, irqflags); + dev_dbg(pfdev->dev, "busy %lu total %lu %lu %% freq %lu MHz\n", status->busy_time, status->total_time, status->busy_time / (status->total_time / 100), @@ -100,6 +102,8 @@ int panfrost_devfreq_init(struct panfrost_device *pfdev) else if (ret) return ret;
+ spin_lock_init(&pfdevfreq->lock); + panfrost_devfreq_reset(pfdevfreq);
cur_freq = clk_get_rate(pfdev->clock); @@ -162,15 +166,32 @@ void panfrost_devfreq_suspend(struct panfrost_device *pfdev)
void panfrost_devfreq_record_busy(struct panfrost_devfreq *pfdevfreq) { + unsigned long irqflags; + + if (!pfdevfreq->devfreq) + return; + + spin_lock_irqsave(&pfdevfreq->lock, irqflags); + panfrost_devfreq_update_utilization(pfdevfreq); - atomic_inc(&pfdevfreq->busy_count); + + pfdevfreq->busy_count++; + + spin_unlock_irqrestore(&pfdevfreq->lock, irqflags); }
void panfrost_devfreq_record_idle(struct panfrost_devfreq *pfdevfreq) { - int count; + unsigned long irqflags; + + if (!pfdevfreq->devfreq) + return; + + spin_lock_irqsave(&pfdevfreq->lock, irqflags);
panfrost_devfreq_update_utilization(pfdevfreq); - count = atomic_dec_if_positive(&pfdevfreq->busy_count); - WARN_ON(count < 0); + + WARN_ON(--pfdevfreq->busy_count < 0); + + spin_unlock_irqrestore(&pfdevfreq->lock, irqflags); } diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.h b/drivers/gpu/drm/panfrost/panfrost_devfreq.h index 0697f8d5aa34..3392df1020be 100644 --- a/drivers/gpu/drm/panfrost/panfrost_devfreq.h +++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.h @@ -4,6 +4,7 @@ #ifndef __PANFROST_DEVFREQ_H__ #define __PANFROST_DEVFREQ_H__
+#include <linux/spinlock.h> #include <linux/ktime.h>
struct devfreq; @@ -14,10 +15,16 @@ struct panfrost_device; struct panfrost_devfreq { struct devfreq *devfreq; struct thermal_cooling_device *cooling; + ktime_t busy_time; ktime_t idle_time; ktime_t time_last_update; - atomic_t busy_count; + int busy_count; + /* + * Protect busy_time, idle_time, time_last_update and busy_count + * because these can be updated concurrently between multiple jobs. + */ + spinlock_t lock; };
int panfrost_devfreq_init(struct panfrost_device *pfdev);